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Description

Navigational Aerial Vehicle Imager, or NAVI for short, is a coaxial, pocket sized (well, I have rather large pockets. Exact dimensions are 200x80mm), 3d printable UAS, that is designed to be cheap, modular, rapidly deployable, and most importantly, extremely portable. It only uses a cyclic swashplate system, rather than cyclic and pitch. This simplifies the mechanism greatly, and allows for a much smaller size. Altitude and yaw control is achieved through varying the RPM of the motors, just like your average multirotor.
The uses range from SAR operations, to battlefield scouting, to just every day aerial videography/photography, in a much smaller package.

Update: 8/8/2017: NAVI is a finalist for the Hackaday Prize! Thanks everyone for all the help and and ideas thus far :) Cheers!

Details

I originally started building 'drones' about 4 and a half years ago, before they were called drones. Autonomous platforms that carry cameras and have a lot of practical use, compared to your usual model aircraft.

Since then, I've always had this thing about trying to make them very small, and very portable. First I started with a folding quad that was still rather large and heavy, but it all fit more or less into a single backpack.

Then I started working on the Maviclone, late last year. As the name implies, it took a fair bit of inspiration from the DJI Mavic Pro.

There were other projects along the way, but these are the most notable, showing major progression in making things smaller and lighter.

And now, NAVI. NAVI is something completely different. No arms to fold out, no bolts to tighten in order to lock said arms in place. You dont need to place it on the ground in order to initialize and take off.

You pull NAVI out of your pocket, hold it in the air, and hit the take off button. Thats it. To retrieve it, you do the inverse. Its simple, its small, and its fast. All traits that are extremely desirable for a search and rescue volunteer, who doesnt want to carry anymore gear than necessary.

Project Logs

This will likely be the last project log prior to the end of the Wings Wheels and Walkers contest. The hardware is pretty much ready for a spin up test, and depending on how that goes, Ill fit the flight controller and try a flight test. However it has been exceedingly hot outside here lately, and I dont feel comfortable testing this inside, so I'm not sure Ill be able to test it before the 24th.

I will get a video put together today or tomorrow, explaining the mechanism (at least as well as I can) and point out a few things that still need worked on.

Apologies again for the long overdue update. Some significant assembly progress is being made, but NAVI still is not ready for a flight test quite yet.

Things left to do is get another set of 2.5mm linkage balls (ordered but shipping from China >.<), design an avionics and battery mounting plate, assemble the rest of the cable harness, and configure the flight controller. Below is a picture of the project as it currently sits, however. Cheers :)

Sorry for the lack of updates everyone. I figured since Hackaday just featured me (massive thanks! :D), I should give a bit of an update as to what's going on. Admittedly, progress slowed to a near stand still for a short time, here's why:

So, swashplate linkages. These linkages are one of the most critical components for making this build work. I tried and tried, multiple iterations, designs, and permutations, to make 3d printable versions of these. While I *believe* its possible, it will take a lot more work. For the time being, in order to hopefully get a test flight in by the Wheels, Wings, and Walkers contest that Ill be entering in, I've ordered TREX Helicopter brand linkages and balls. These are proven reliable and smooth, and should be more than adequate for NAVI. I'm now just waiting for those to show up, ETA is Monday or Tuesday (5/15, 5/16)

Once I have those in hand, all that's left is to mount them up and adjust them. After that, print the avionics and battery sled to hold those in place, and a temporary 'tripod' landing gear, so I dont have to have my hands near the blades during the trial take-offs/landings. Thats about it, and we'll be ready for a test flight!

Assuming the test flight goes according to plan: Any tweaks that need made to improve performance will be made, and then I will print the shell, mount the cameras (yes, thats plural, more on that later ;) ) At that point, NAVI Mk1 will be considered "Completed." (A project like this is never truly done...)

What happens after that? Well I have a couple other highly portable, quickly deployable designs I want to play with. When those are out of the way, NAVI Mk2 development will begin. Goals for Mk2 is to integrate GPS and other sensors to facilitate full, proper autonomy. This requires a larger diameter CF center tube to carry the cables, which in turn requires a near complete redesign. I'm sure there will be other changes that I will make along the way, using the knowledge gained from NAVI Mk1.

Thanks again for all the helpful comments, likes, and follows. Please keep an eye out for the test flight of NAVI, and my entry into the Wheels Wings and Walkers challenge! Cheers :)

I have 3D printed a good majority of the parts, have gone back and tweaked them, and reprinted more. I've started assembly as well, and am aiming for a flight test the first week of May, sans the outer shell. I've uploaded the files as they are now, however I would discourage you from printing them, as almost any are subject to change prior to the test flight. Feel free to dig around and make suggestions however :)

Below are pictures of both the partially assembled NAVI MK1, as well as the CAD renders as they currently sit.

I have been working more on getting NAVI's parts printed and assembled. This is a rather tedious build, with lots of small tweaks that need to be made, so most of the work isnt worth writing a log about, but I'm definitely still working on NAVI! Here's a more recent image (however not indicative of its current progress) of NAVI, compared to a tape measure and average 28oz double wall water bottle.

You can also see the NCR18650B cell-based 4s pack I'm putting together to power this bird.

Anyways, just a quick little update. Hoping for a test flight this weekend :)

I've uploaded a Part 1 video on printing and assembly of NAVI. I've also decided to change my initial plan of using Black Widow 1200kv motors, instead opting for 920kv motors and external ESCs (they are however round, and the diameter of the motor, so I will make a custom adapter to mount them as if they were integrated,maximizing use of available space.)

I've also gone through and designed 3d printable gears that thread onto the motor's shaft as if it were a standard prop, and will be testing those. If those dont hold up well, I'll either switch to a belt drive, or have the gears printed in metal or SLS nylon through shapeways.

Just waiting on black ABS filament to show up, to be able to print the rest of the bits :)

I have been working a bit more on NAVI's CAD. The details arent too
terribly interesting, and are just minor mechanical things. Here are
some updated images. I will be ordering the motors (Using 2208 1200kv
Black Widows with integrated ESCs), batteries (Going with a custom 18650
cell based pack, using NCR18650GA cells in a 3s assembly. Using these
over LiPo as they can source the needed current and have a higher energy
density.) the carbon fiber tube, bearings, and some other bits in the
next day or two. Once those arrive, things get interesting :) I intend
to do a video on putting NAVI together, or at the very least, there will
be images of its assembly. This has been a fun challenge thus far, and
should continue to prove interesting :) Thanks for all the love and
support, heres to getting NAVI flying in under 2 weeks time, just in
time for a family barbecue! :)

There are still some more things to
be designed/addressed, such as the motor mount, however they are pretty
trivial. Just need to get the motors in hand for precise measurements.

So far I have been able to maintain my 200mm length, 80mm diameter goals. Hoping I can keep it that way :)

Can't wait to see the code because I have a strong feeling it will be pretty crazy. Just to program a quadcopter is a difficult task, I can't imagine having to make working software for this kind of drone :)

hey this project has given me some inspiration. Thanks! I don't build drones but I'm extremely interested in the system you're using for driving the two blade sets . If you're getting slip with the drive gears perhaps an adjustable gear opposite the motor for reinforcement.

I had problems with sloppy linkages and the control ams sticking at certain angles with 3d printed parts. So yeah you are right going with proper copter linkages. I originally started out with a printed gimballed swash, but ended up using a hirobo swash i had on hand. Your ball swash looks smashing. Keep up the good work!

Sorry for the late reply! Yeah we span the thing, the gear were printed in PLA and the gears help up okay. I used a herringbone gear on one and a helical gear on the other with a view of increasing the surface area in contact. So i was just testing.